Safety concerns for tourists vary in type in countries. Some have insect concerns, eg. types of spider bites to avoid. Other countries have diseases which people should take vaccines for prior to departure. Some countries have crime levels which may be high, or only high enough for concern in large cities etc. Or even that emergency medical treatment may not be of a good standard in certain places.

When planning a trip these issues are encountered many times late in the planning losing a lot of time. Are there good sources which compile this information?

These sites give you very detailed and up-to-date information on the topics you have mentioned.

Health and safety concerns are also covered by any good travel guidebook. It is clear that this information might not be up-to-date. You can also find some hints in the country fiches published on the websites of these travel guidebooks.

I'm almost always check the websites of the ministries of foreign affairs of my neighboring countries.

The reason that I choose neighboring countries is easy: my own country is too small to have such information. And I think neighboring countries have more or less the same safety standard and culture so that their evaluation of a safety situation in other countries will fit to my personal estimation.

This site is also very useful. It is in German, but it is obvious how to use it. Just choose a country on the Map and then you will get a link collection for this country. A lot of these links are then available in English. An advantage of this site is that you'll see the general situation of the whole world in an overview.

If you are travelling with a printed travel guide book they should all have a relevant section to address your concerns.

For instance in Lonely Planet travel guides there will be a section called Dangers and annoyances.

For Australian citizens there are "travel advisories" issued by the government. They seem to change their name from time to time for no good reason. Right now it's called "Smartraveller" and has a website at www.smartraveller.gov.au, in my experience though they are pretty good at making just about any potential destination seem scary. I'm sure they could issue a warning about Australia if they felt like it saying "Many dangerous animals, snakes, and spiders" for instance (-: